ASP中取得图片宽度和高度的类

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Class ImgWHInfo '获取图片宽度和高度的类，支持JPG，GIF，PNG，BMP
Dim ASO
Private Sub Class_Initialize
  Set ASO=Server.CreateObject("ADODB.Stream")
  ASO.Mode=3
  ASO.Type=1
  ASO.Open
End Sub
Private Sub Class_Terminate
  Err.Clear
  Set ASO=Nothing
End Sub
 
Private Function Bin2Str(Bin)
  Dim I, Str
  For I=1 To LenB(Bin)
   clow=MidB(Bin,I,1)
   If ASCB(clow)<128 Then
Str = Str & Chr(ASCB(clow))
   Else
I=I+1
If I <= LenB(Bin) Then Str = Str & Chr(ASCW(MidB(Bin,I,1)&clow))
   End If
  Next
  Bin2Str = Str
End Function
  
Private Function Num2Str(Num,Base,Lens)
  Dim Ret
  Ret = ""
  While(Num>=Base)
   Ret = (Num Mod Base) & Ret
   Num = (Num - Num Mod Base)/Base
  Wend
  Num2Str = Right(String(Lens,"0") & Num & Ret,Lens)
End Function
  
Private Function Str2Num(Str,Base)
  Dim Ret,I
  Ret = 0
  For I=1 To Len(Str)
   Ret = Ret *base + Cint(Mid(Str,I,1))
  Next
  Str2Num=Ret
End Function
  
Private Function BinVal(Bin)
  Dim Ret,I
  Ret = 0
  For I = LenB(Bin) To 1 Step -1
   Ret = Ret *256 + AscB(MidB(Bin,I,1))
  Next
  BinVal=Ret
End Function
  
Private Function BinVal2(Bin)
  Dim Ret,I
  Ret = 0
  For I = 1 To LenB(Bin)
   Ret = Ret *256 + AscB(MidB(Bin,I,1))
  Next
  BinVal2=Ret
End Function
  
Private Function GetImageSize(filespec)
  Dim bFlag
  Dim Ret(3)
  ASO.LoadFromFile(filespec)
  bFlag=ASO.Read(3)
  Select Case Hex(binVal(bFlag))
  Case "4E5089":
   ASO.Read(15)
   ret(0)="PNG"
   ret(1)=BinVal2(ASO.Read(2))
   ASO.Read(2)
   ret(2)=BinVal2(ASO.Read(2))
  Case "464947":
   ASO.read(3)
   ret(0)="gif"
   ret(1)=BinVal(ASO.Read(2))
   ret(2)=BinVal(ASO.Read(2))
  Case "535746":
   ASO.read(5)
   binData=ASO.Read(1)
   sConv=Num2Str(ascb(binData),2 ,8)
   nBits=Str2Num(left(sConv,5),2)
   sConv=mid(sConv,6)
   While(len(sConv)<nBits*4)
binData=ASO.Read(1)
sConv=sConv&Num2Str(AscB(binData),2 ,8)
   Wend
   ret(0)="SWF"
   ret(1)=Int(Abs(Str2Num(Mid(sConv,1*nBits+1,nBits),2)-Str2Num(Mid(sConv,0*nBits+1,nBits),2))/20)
   ret(2)=Int(Abs(Str2Num(Mid(sConv,3*nBits+1,nBits),2)-Str2Num(Mid(sConv,2*nBits+1,nBits),2))/20)
  Case "FFD8FF":
   Do 
   Do: p1=binVal(ASO.Read(1)): Loop While p1=255 And Not ASO.EOS
   If p1>191 And p1<196 Then Exit Do Else ASO.read(binval2(ASO.Read(2))-2)
   Do:p1=binVal(ASO.Read(1)):Loop While p1<255 And Not ASO.EOS
   Loop While True
   ASO.Read(3)
   ret(0)="JPG"
   ret(2)=binval2(ASO.Read(2))
   ret(1)=binval2(ASO.Read(2))
  Case Else:
   If left(Bin2Str(bFlag),2)="BM" Then
ASO.Read(15)
ret(0)="BMP"
ret(1)=binval(ASO.Read(4))
ret(2)=binval(ASO.Read(4))
   Else
  ret(0)=""
   End If
  End Select
  ret(3)="width=""" & ret(1) &""" height=""" & ret(2) &""""
  getimagesize=ret
End Function
  
Public Function imgW(IMGPath)
  Dim FSO,IMGFile,FileExt,Arr
  Set FSO = Server.CreateObject("Scripting.FileSystemObject")
  If (FSO.FileExists(IMGPath)) Then
   Set IMGFile = FSO.GetFile(IMGPath)
   FileExt=FSO.GetExtensionName(IMGPath)
   Select Case FileExt
Case "gif","bmp","jpg","png":
Arr=GetImageSize(IMGFile.Path)
imgW = Arr(1)
   End Select
   Set IMGFile=Nothing
  Else
   imgW = 0
  End If 
  Set FSO=Nothing
End Function
 
Public Function imgH(IMGPath)
  Dim FSO,IMGFile,FileExt,Arr
  Set FSO = server.CreateObject("Scripting.FileSystemObject")
  If (FSO.FileExists(IMGPath)) Then
   Set IMGFile = FSO.GetFile(IMGPath)
   FileExt=FSO.GetExtensionName(IMGPath)
   Select Case FileExt
Case "gif","bmp","jpg","png":
Arr=getImageSize(IMGFile.Path)
imgH = Arr(2)
   End Select
   Set IMGFile=Nothing
  Else
   imgH = 0
  End If 
  Set FSO=Nothing
End Function
End Class

IMGPath="Test.jpg"

Set PP = New ImgWHInfo 
W = PP.imgW(Server.Mappath(IMGPath)) 
H = PP.imgH(Server.Mappath(IMGPath))
Set pp = Nothing
 
Response.Write("<img src='"&IMGPath&"' border=0><br>宽:"&W&";高:"&H)
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